Conventional data recording disk files utilize one or more rotatable disks with concentric data tracks, one or more heads for reaching or writing data onto the various tracks, and an actuator connected by a support arm assembly to the heads for moving the heads to the desired tracks and maintaining them over the track centerlines during read or write operations. The disks are mounted in a stack on a spindle, which includes a rotatable shaft, a bearing assembly supporting the shaft to the disk file frame or base plate, and a hub located at the end of the shaft. In certain disk files the disk file housing, which typically includes the base plate and a cover plate, is generally sealed and air within the housing is circulated by the pumping action of the rotating disks. In these disk files the hub has a plurality of apertures and the disks are separated by disk spacers which contain openings communicating with the apertures. As the disks rotate, air is drawn through the hub apertures and disk spacer openings, out across the disk surfaces and expelled at the periphery of the disks. The air from the periphery of the disks is then directed back to the bottom of the hub for recirculation.
The actuator in conventional data recording disk files is typically a "voice coil motor" (VCM) which comprises a coil movable through the magnetic field of a permanent magnetic stator. The application of current to the VCM causes the coil, and thus the attached heads, to move radially to access the concentric data tracks on the disks. The read/write circuitry which is electrically connected to the heads is typically contained in electronic modules which are required to be mounted close to the heads, such as on the support arm connecting the heads to the actuator. In sealed disk files, because both the coil of the VCM and the electornic modules are sources of heat, they must be efficiently cooled by the air recirculated by the pumping action of the rotating disks. Conventional sealed disk files do not confine or direct the air flow from the periphery of the disks to any specific component within the disk file, but merely allow the air to flow across the arm and coil in a direction which, in the case of linear VCMs, is generally parallel to the linear path of the coil. The flow of the air in this manner does not efficiently cool the electronic modules and coil and in fact generates a relatively low frequency bias force, referred to as "windage", which is continually acting on the coil. This force causes the heads to be maintained off track during read or write operations and must thus be effectively compensated by the disk file servo control system to maintain the heads directly over the track centerlines.